This invention relates to a prefabricated, prestressed bridge system and a method for making same. Prefabricated, prestressed bridges are commonly known, however, the prefabricated, prestressed bridges currently available are cumbersome to manufacture and difficult to erect resulting in an expensive, labor-intensive final product. Prefabricated, prestressed bridges are used in a variety of civil engineering applications such as disclosed in U.S. Pat. No. 5,471,694 Prefabricated Bridge with Prestressed Elements (“Meheen patent”); U.S. Pat. No. 4,493,177 Composite, Pre-Stressed Structural Member and Method for Forming Same (“Grossman patent”); and U.S. Pat. No. 2,373,072 Rigid Frame Bridge and Method of Making the Same (“Wichert patent”). However, improvements are desired to provide a more easily manufacturable, more robust system with more integrated components which assist in providing the prestress to the bridge beams. Implementation of these improvements results in lower cost and increased speed of construction of a prefabricated, prestressed bridge system.
The Meheen patent discloses a prefabricated bridge beam with prestressed elements comprising a rectangular girder-box assembly which includes a bottom plate prestressed in compression and a pair of upstanding side members each having its upper portions prestressed in tension. A poured and cured bridge deck is supported by the said side members, the cured deck securing in place the said tension and compression stresses. However, the Meehan bridge beam utilizes a cantilevered load to deform the bridge beam. And, the Meehan beam lacks integrated structural members that provide constant, localized loads for prestressing.
The Grossman patent discloses a composite, prestressed structural member comprised of concrete and a lower metal support member, and a method for forming and prestressing the same. However, the Grossman structural member requires inversion to a concrete-uppermost position prior to use.
The Wichert patent relates to rigid frame bridges and the fabrication and construction thereof. The Wichert method for fabricating the rigid frame bridge discloses holding the metal span portion of the bridge against sagging upon application of the concrete or, alternatively, positively pressing upwardly the metal span portion prior to pouring the concrete. However, the Wichert rigid frame bridge does not utilize integrated structural members to achieve prestressing.
Accordingly, an apparatus, system, and method are desired for solving the aforementioned problems and providing the aforementioned advantages.